2-haloaromatic fluoride compounds, such as 2-bromofluorobenzene, are useful as intermediates in making other compounds. For example, 2-bromofluorobenzene is useful as a starting material for the synthesis of 2-fluorophenol, which in turn is useful as an intermediate for several agricultural, pharmaceutical and polymer compounds. Known methods of producing these compounds include the Sandmeyer and Schiemann reactions. For example, using the Sandmeyer reaction, 2-bromofluorobenzene can be produced from 2-fluoroaniline as shown below: ##STR1##
Using the Schiemann reaction, 2-bromofluorobenzene can be produced from 2-bromoaniline as shown below: ##STR2## In an alternative version of the Schiemann reaction, hexafluorophosphoric acid is used to produce 2-bromofluoro-benzene from 2-bromoaniline: ##STR3## Preparation of haloaromatic compounds using the Sandmeyer and Schiemann reactions is generally discussed by Streitweiser and Heathcock, Introduction to Organic Chemistry, (2d. Ed., 1981), pages 794-795. The modified Schiemann reaction for producing 2-bromofluorobenzene using HPF.sub.6 is discussed in the same reference at page 796.
There are disadvantages associated with using each of the above reactions for preparing 2-halofluorobenzenes. Some of the starting materials, such as 2-bromoaniline, are relatively expensive, and the reactions produce low yields of products and are fairly hazardous due to the high decomposition temperature of the intermediate diazonium compound. Therefore, a need exists for a process that employs less expensive, more readily available starting materials and utilizes less hazardous reactions to produce 2-halofluorobenzenes.